US5967461A - High efficiency environmental control systems and methods - Google Patents

High efficiency environmental control systems and methods Download PDF

Info

Publication number
US5967461A
US5967461A US08/887,018 US88701897A US5967461A US 5967461 A US5967461 A US 5967461A US 88701897 A US88701897 A US 88701897A US 5967461 A US5967461 A US 5967461A
Authority
US
United States
Prior art keywords
cabin
turbine
air
outlet
inlet
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US08/887,018
Other languages
English (en)
Inventor
Franklin D. Farrington
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
McDonnell Douglas Corp
Original Assignee
McDonnell Douglas Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=25390283&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=US5967461(A) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by McDonnell Douglas Corp filed Critical McDonnell Douglas Corp
Priority to US08/887,018 priority Critical patent/US5967461A/en
Assigned to MCDONNELL DOUGLAS CORPORATION reassignment MCDONNELL DOUGLAS CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FARRINGTON, FRANKLIN D.
Priority to DE69835054T priority patent/DE69835054T3/de
Priority to EP98111967A priority patent/EP0888966B2/de
Application granted granted Critical
Publication of US5967461A publication Critical patent/US5967461A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B64AIRCRAFT; AVIATION; COSMONAUTICS
    • B64DEQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
    • B64D13/00Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space, or structural parts of the aircraft
    • B64D13/06Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space, or structural parts of the aircraft the air being conditioned
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B64AIRCRAFT; AVIATION; COSMONAUTICS
    • B64DEQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
    • B64D13/00Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space, or structural parts of the aircraft
    • B64D13/06Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space, or structural parts of the aircraft the air being conditioned
    • B64D2013/0603Environmental Control Systems
    • B64D2013/0618Environmental Control Systems with arrangements for reducing or managing bleed air, using another air source, e.g. ram air
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B64AIRCRAFT; AVIATION; COSMONAUTICS
    • B64DEQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
    • B64D13/00Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space, or structural parts of the aircraft
    • B64D13/06Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space, or structural parts of the aircraft the air being conditioned
    • B64D2013/0603Environmental Control Systems
    • B64D2013/0644Environmental Control Systems including electric motors or generators
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B64AIRCRAFT; AVIATION; COSMONAUTICS
    • B64DEQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
    • B64D13/00Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space, or structural parts of the aircraft
    • B64D13/06Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space, or structural parts of the aircraft the air being conditioned
    • B64D2013/0603Environmental Control Systems
    • B64D2013/0648Environmental Control Systems with energy recovery means, e.g. using turbines
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B64AIRCRAFT; AVIATION; COSMONAUTICS
    • B64DEQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
    • B64D13/00Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space, or structural parts of the aircraft
    • B64D13/06Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space, or structural parts of the aircraft the air being conditioned
    • B64D2013/0603Environmental Control Systems
    • B64D2013/0688Environmental Control Systems with means for recirculating cabin air
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T50/00Aeronautics or air transport
    • Y02T50/40Weight reduction
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T50/00Aeronautics or air transport
    • Y02T50/50On board measures aiming to increase energy efficiency

Definitions

  • the present invention relates to high efficiency environmental control systems for vehicles powered by turbine engines which recover energy from air exiting a controlled pressurized space.
  • a common approach to environmental control system design for vehicles using turbo machines is based on the air cycle machine or "pack".
  • the pack outputs cool air at a pressure sufficient to move the air through distribution ducts and at a rate sufficient to satisfy the fresh air needs of the occupants (while also compensating for intentional and unintentional outward leaks).
  • the air cycle machine is said to emulate the "air-standard refrigeration cycle" found in thermodynamic texts.
  • differences exist which provide the opportunity for increasing efficiency of the traditional air cycle machine approach.
  • the typical air cycle machine extracts an amount of "bleed air" from the engine core compressor ports, such as the eighth stage (low stage bleed air) or fourteenth stage (high stage bleed air).
  • the bleed air is compressed or pressurized and as a result heated to a very high temperature relative to ambient.
  • the bleed air is then passed through a compressor which further increases the temperature and pressure.
  • Ram air flow is used to cool the compressed bleed air before it is expanded and further cooled in a turbine to an appropriate temperature and pressure to operate a water separateor and cool the controlled space, generally referred to herein as the cabin.
  • bleed air In terms of engine fuel consumption, bleed air is very expensive. For example, in a typical aircraft application cruising at 35,000 feet, one pound per second (pps) of low stage bleed air costs the same as 158 kilowatts (211 hp) of shaft power extracted from a gearbox coupled to the engine: 1.2% specific fuel consumption (SFC). Furthermore, fan air used to precool the bleed air before passing it to the compressor may add an additional 0.52% SFC. As such, it is desirable to reduce or eliminate the use of bleed air to increase efficiency of the environmental control system. Alternatively, it is desirable to fully utilize the energy of the bleed air.
  • pps pound per second
  • SFC specific fuel consumption
  • cabin or fuselage pressure is regulated by restricting outflow of air through an outflow valve.
  • the outflow valve has an open area modulated to provide a desired pressure.
  • the rate of air supplied must equal the rate of air leaked plus the rate of air exhausted through the outflow valve.
  • the outflow valve is carefully shaped to form a converging-diverging supersonic nozzle since the pressure ratio allows an exit Mach number of about 1.6 in a single process.
  • the actual savings in % SFC are difficult to isolate and measure due to various factors, such as the possibility of creating an adverse yaw moment which requires rudder compensation thereby leading to additional aerodynamic drag. As such, it is desirable to provide an alternative approach to energy recovery to improve the efficiency of the environmental control system.
  • a general object of the present invention is to improve the efficiency of an environmental control system for a pressurized cabin, such as those typical of aircraft. This object is accomplished by recovering energy from the air exhausted from the cabin using a variety of alternative environmental control system configurations.
  • a high efficiency environmental control system includes a heat exchanger which uses air exhausted from the cabin to cool air supplied to the cabin.
  • the system may be configured in any of a number of alternative embodiments to realize the features and advantages of the present invention to recover energy from air exhausted from a pressurized space.
  • Various embodiments employ alternative configurations which are selectively utilized based on current cooling demands to further improve system efficiency.
  • a heat exchanger having a first inlet and corresponding first outlet is placed in fluid communication with the outflow port of the cabin.
  • the heat exchanger includes a second inlet and corresponding second outlet in fluid communication with the inflow port of the cabin.
  • air exhausted from the cabin passes through the first inlet and outlet of the heat exchanger to cool air supplied to the cabin through the second inlet and outlet to increase efficiency of the system.
  • a fan interposed the first inlet of the heat exchanger and the outflow port of the cabin may be used for moving air through the heat exchanger.
  • air exiting the outflow port is passed through a turbine interposed the cabin and the heat exchanger such that the turbine expands and cools the air exhausted from the cabin to further cool the air supplied to the cabin through the second inlet and outlet of the heat exchanger.
  • the turbine may be used to drive a compressor which is mechanically coupled to the turbine.
  • the compressor receives ram air and compresses the ram air (relative to ambient) to provide compressed air to the compressor outlet.
  • the compressed air is passed through the heat exchanger where it is cooled prior to entering the controlled space or cabin.
  • a second turbine which is mechanically coupled to the compressor.
  • the second turbine receives bleed air from at least one engine and has an outlet in fluid communication with the heat exchanger.
  • a motor may be coupled to the compressor for providing energy to drive the compressor.
  • the motor receives electrical power from a generator coupled to one of the engines.
  • the present invention recovers energy from air exhausted from the cabin to improve efficiency of the environmental control system.
  • the present invention provides a number of alternatives to reduce or eliminate the use of bleed air from one or more turbine engines. While particularly suited for aircraft applications, the present invention may be utilized for any application having a pressurized space or cabin.
  • FIG. 1 is a schematic representation of one embodiment of the present invention referred to as a minimum bleed configuration where the dotted lines represent conditions allowing adequate low temperature air to be supplied to the water separator;
  • FIG. 2 is a schematic block diagram of another embodiment of the present invention referred to as an all-electric configuration
  • FIG. 3 is a schematic block diagram of another configuration for the present invention illustrating an all-electric configuration under maximum cooling demand
  • FIG. 4 is a schematic block diagram illustrating an ECS configuration using an outflow turbine and bleed turbine to drive corresponding generators
  • FIG. 5 illustrates another alternative configuration using an outflow turbine, ram air compressor, and a second turbine and motor to drive the compressor in an all-electric configuration
  • FIG. 6 illustrates an alternative minimum bleed configuration using switch dampers to alter the configuration based on cooling demand
  • FIG. 7 illustrates a minimum bleed configuration using switch dampers in a maximum economy mode.
  • ECS 10 provides fresh, pressurized or compressed air to a controlled space such as cabin 12.
  • cabin refers to the entire volume within the pressurized shell of an enclosed space such as the fuselage of an aircraft.
  • cabin 12 includes one or more inflow ports, indicated generally by reference numeral 14, for supplying fresh, pressurized air to cabin 12.
  • the pressure within cabin 12 may be regulated by restricting the air exiting cabin 12 through an outflow port, indicated generally by reference numeral 16.
  • air passing through outflow port 16 is restricted by varying turbine parameters, as described in greater detail herein.
  • an outflow valve may be used where required in combination with varying turbine inlet geometry.
  • the rate of air supplied through inflow port 14 must be equal to the air exhausted from cabin 12 through outflow port 16 in addition to air lost through leaks, indicated generally by reference numeral 18.
  • the leaks represent both intentional and unintentional outward flow of air such as may occur through door seals, or pressure shell penetrations by tubes, wires, and the like.
  • double arrows are used to indicate air exhausted to atmosphere, or ambient.
  • ECS 10 is powered by at least one turbine engine 20.
  • three such turbine engines are used to power an aircraft.
  • Ram air indicated generally by reference numeral 22, enters engine 20 through fan 24 before passing through multi-stage compressor 26.
  • the compressed air is fed to a combustion chamber 28 where it is mixed with fuel from a fuel source 30.
  • the combustion process is used to drive turbine 32 which is mechanically coupled by shaft 34 to compressor 26.
  • the jet exhaust then passes to atmosphere as indicated generally by reference numeral 36.
  • a transmission or gear box 38 is mechanically coupled to shaft 34 to selectively drive a generator 40 which generates electrical power, generally indicated by reference numeral 42, to meet the electrical demands of the vehicle.
  • Air may be extracted from engine 20 from fan 24 as indicated by reference numeral 44 or from a bleed port 46.
  • Reference numeral 46 represents both high stage, and low stage bleed air.
  • low stage bleed air is extracted from the eighth stage of multi-stage compressor 26 whereas high stage bleed air is extracted from the fourteenth stage of multi-stage compressor 26.
  • the embodiment illustrated in FIG. 1 may be referred to as a minimum bleed configuration since the bleed air extracted is reduced from the prior art requirement of about 7.5 pounds (mass) per second (pps) to about 4 pps.
  • Bleed air (high stage or low stage) is extracted from bleed port 46 and passes through a pre-cooler 48 where it is cooled by fan air 44.
  • pre-cooler 44 is a cross-flow, non-mixing, air-to-air heat exchanger which exhausts the cross-flow air to atmosphere as indicated by reference numeral 50. Due to the reduced flow requirements, pre-cooler 48 need reject only about 345 kw as opposed to the prior art design which requires heat rejection of about 640 kw. As such, less air is required from fan 24 to achieve the required cooling. This may contribute to savings in percent SFC as described herein.
  • a portion of the air exiting pre-cooler 48 is diverted as indicated by reference numeral 52 to provide anti-ice functions for the aircraft.
  • the remaining air flow is directed into one or more packs 54 for cooling prior to being supplied to cabin 12.
  • an aircraft may have one pack associated with each engine, multiple engines associated with a single pack, or multiple packs associated with one or more engines.
  • pack 54 represents one or more packs which satisfy the cooling and fresh air requirements for cabin 12.
  • Air entering pack 54 may be routed through a first path, indicated generally by reference numeral 56, or a second path, indicated generally by reference numeral 58, depending upon the particular cooling demand and pressure differential between cabin 12 and ambient.
  • the path indicated by solid lines 56 represents the path used to provide maximum cooling to an aircraft on a hot, humid day during a sea level climb.
  • path 56 routes bleed air from pre-cooler 48 to heat exchanger 60.
  • Heat exchanger 60 includes a first inlet and corresponding first outlet in fluid communication with outflow port 16 of cabin 12.
  • Heat exchanger 60 also includes a second inlet and corresponding second outlet in fluid communication with inflow port 14 of cabin 12. As such, air exhausted from cabin 12 passes through the first inlet and outlet of heat exchanger 60 to cool air supplied to cabin 12 through the second inlet and outlet to increase the efficiency of the system.
  • heat exchanger 60 may be alternatively placed in fluid communication with inflow port 14 of cabin 12 through water separator 62 either directly, as indicated by dashed line 64, or through turbine 66 depending upon the cooling demand of cabin 12.
  • a compressor 68 receives ram air 22 through a compressor inlet to provide compressed air at the compressor outlet which is mixed with bleed air from engine 20 before entering second inlet of heat exchanger 60.
  • Compressor 68 is mechanically coupled to and driven by turbine 66.
  • Compressor 68 may also be driven by a second turbine 70 which is mechanically coupled thereto via shaft 72 when operating in the high efficiency mode, such as during cruising at altitude.
  • Second turbine 70 is driven by bleed air from engine 20 as indicated generally by reference numeral 58.
  • turbine 70 is selectively mechanically coupled to compressor 68 when functioning in the maximum efficiency or economy mode.
  • the outlet of turbine 70 is then in fluid communication with the outlet of compressor 68 where air is mixed prior to entering the second inlet of heat exchanger 60.
  • ram air may be provided during economy mode through path 74.
  • a low pressure fan 76 may be used to extract available cooling effect from air exiting cabin 12 through outflow port 16.
  • Low pressure fan 76 is used to provide a sufficient air flow when a reduced pressure ratio exists between cabin 12 and atmosphere or ambient, such as typically occurs at or near sea level. Air exiting the first outlet of heat exchanger 60 is exhausted to ambient as indicated generally by reference numeral 78.
  • the minimum bleed configuration illustrated in FIG. 1 is based on providing the majority, if not all, of the cabin air from compression of ram air through compressor 68.
  • the duty of such a compressor is constant in mass flow rate and requires pressure rises far smaller than those produced at the bleed stage of the engines. This approach recovers as much energy as possible from air exiting cabin 12 through outflow port 16. In the maximum economy mode, this air is passed through turbine 66 whose power is used to partially supply the energy to drive compressor 68 via shaft 80.
  • the outflow air has considerable available energy with respect to the outside ambient in most flight regimes other than at low altitudes.
  • turbine 66 having an adiabatic efficiency of 80% would be able to recover 29.5 kw for each pps of air flow.
  • the energy available from the outflow air of about 5 pps can be recovered which amounts to around 150 kw.
  • Use of turbine 66 also provides another serendipitous effect: the air exiting turbine 66 is significantly cooler than ambient air such that it serves as an excellent heat sink for the heat exchange process of pack 54.
  • the additional power to drive compressor 68 may be provided by the selectably engageable turbine 70 or alternatively by a motor, as illustrated and described herein.
  • heat exchanger 60 can be smaller than the existing heat exchanger resulting in attendant savings in manufacturing costs and fuel cost during operation.
  • the high efficiency configuration indicated by dashed lines in FIG. 1 is modified to the maximum cooling configuration as indicated by the double solid lines of FIG. 1.
  • the exhaust air from the cabin still provides a better heat sink than the ambient air so low pressure fan 76 is included to move the exhaust air through heat exchanger 60.
  • ram air is compressed by compressor 68 up to the bleed pressure and merged with bleed air prior to being cooled in heat exchanger 60.
  • Turbine 66 is then used to expand and cool the supply air prior to entering water separator 62 and distribution ducts within cabin 12.
  • FIGS. 2 and 3 another embodiment of an environmental control system according to the present invention is shown.
  • This embodiment may be referred to as an "all-electric" configuration since the use of bleed air from engine 20 has been eliminated.
  • FIG. 2 illustrates the all-electric configuration having flows selectively arranged for maximum economy
  • FIG. 3 illustrates the flows to achieve maximum cooling.
  • FIG. 2 is described using representative calculations for a 35,000 foot cruise, while FIG. 3 uses representative calculations for a hot day sea level climb.
  • Like reference numerals indicate similarity of function for components illustrated and described with reference to FIG. 1.
  • One of ordinary skill in the art will recognize that various flow rates, heat exchanger parameters, and other such considerations will vary depending upon the particular application.
  • pre-cooler 48 of FIGS. 2 and 3 appears schematically identical to pre-cooler 48 of FIG. 1, the pre-cooler of FIGS. 2 and 3 must provide less heat rejection since the bleed air has been eliminated from the ECS function. As such, bleed air through pre-cooler 48 of FIGS. 2 and 3 is provided only for the anti-ice function, indicated generally by reference numeral 52.
  • the all-electric configuration illustrated in FIGS. 2 and 3 may require a larger gear box 38 and generator 40 than the corresponding components of FIG. 1 to accommodate the increased electrical demand.
  • generator 40 For the maximum economy mode illustrated in FIG. 2, generator 40 must provide 165 kw of electrical power to cabin 12 in addition to approximately 143 kw of electrical power for motor 100 which is mechanically coupled to compressor 68 via shaft 72. Due to the approximate conversion efficiency of 90% used for motor 100, the 143 kw of electrical power is converted to about 129 kw of mechanical power transmitted to compressor 68 via shaft 72.
  • compressor 68 pressurizes ram air 22 which passes through heat exchanger 102 where it is cooled using air exhausted from cabin 12 through outflow port 16.
  • Turbine 66 is mechanically coupled to compressor 68 via shaft 80.
  • Turbine 66 includes an inlet in fluid communication with outflow port 16 of cabin 12 and an outlet in fluid communication with a first inlet and corresponding first outlet of heat exchanger 102 to cool the air exiting compressor 68 and passing through a second inlet and corresponding second outlet of heat exchanger 102.
  • Turbine 66 expands and cools air exhausted from cabin 12 to generate about 156 kw of mechanical power to drive compressor 68 via shaft 80.
  • additional ram air 22 may be provided via path 74 to the first inlet and outlet of heat exchanger 102 to increase the heat rejection.
  • heat exchanger 102 rejects about 293 kw of thermal energy but requires an effectiveness of about 0.93 to accommodate the maximum cooling regime illustrated in FIG. 3.
  • FIG. 2 To provide maximum cooling on a hot day at low altitude, the configuration of FIG. 2 is modified via appropriate mechanization to achieve the configuration of FIG. 3. Under these conditions, generator 40 must provide about 235 kw of electrical power to motor 100 in addition to the 165 kw of electrical power required for various equipment within cabin 12. As such, generator 40, motor 100, and gear box 38 should be sized accordingly.
  • compressor 68 receives ram air 22 and delivers pressurized air to second inlet and corresponding second outlet of heat exchanger 102, similar to the configuration of FIG. 2. However, the second outlet of heat exchanger 102 is in fluid communication with the inlet of turbine 66 which expands and cools the air prior to entering water separator 62 and passing through inflow port 14 of cabin 12.
  • Fan 76 is used to provide additional air flow through first inlet and outlet of heat exchanger 102 since the pressure differential between cabin 12 and atmosphere is insufficient to provide the necessary heat rejection, approximately 370 kw, by heat exchanger 102.
  • Motor 100 provides about 211 kw of mechanical power to drive compressor 68 via shaft 72.
  • Compressor 68 is also driven via shaft 80 by turbine 66 which provides an additional 181 kw of mechanical power.
  • Fan 76 requires about 2 kw of electrical power which is incorporated into the power demand of the cabin equipment.
  • the environmental control system illustrated in FIGS. 2 and 3 includes compressor 68 which receives ram air 22 through a compressor inlet to provide compressed air at the compressor outlet.
  • Heat exchanger 102 includes a first inlet and corresponding first outlet for cooling air from compressor 68 which passes through a second inlet and corresponding second outlet.
  • the first inlet of heat exchanger 102 is in fluid communication with outflow port 16 of cabin 12 when the system is in the maximum cooling mode while being in communication with the outlet of turbine 66 when the system is in the maximum economy mode.
  • Turbine 66 is mechanically coupled to compressor 68 and includes an inlet in fluid communication with the second outlet port of heat exchanger 102 when the system is in the maximum cooling mode and in fluid communication with outflow port 16 when the system is in the maximum economy mode.
  • Turbine 66 also includes an outlet in communication with inflow port 14 of cabin 12 when the system is in the maximum cooling mode, but in fluid communication with the second inlet of heat exchanger 102 when the system is in the economy mode. As such, heat exchanger 102 recovers available energy from air exhausted through outflow port 16 to cool air supplied to cabin 12 through inflow port 14.
  • This configuration includes motor 100 which is mechanically coupled to compressor 68 for driving the compressor while functioning in both the maximum cooling mode and the economy mode.
  • FIG. 4 another embodiment of an environmental control system according to the present invention is shown.
  • the hexagons of FIG. 4 are used to identify representative values for temperatures and pressures of air at various points throughout the system as summarized in Table 1 below.
  • this configuration may be referred to as a "full bleed flow configuration”.
  • This arrangement provides electrical recovery of both outflow air and bleed air energy which is eventually converted back to mechanical energy provided to engine 20 through a motor 110.
  • a first turbine 112 is interposed cabin 12 and heat exchanger 114 such that the inlet of turbine 112 is in fluid communication with outflow port 16 of cabin 12, while the outlet of turbine 112 is in fluid communication with the first inlet and corresponding first outlet of heat exchanger 114.
  • Turbine 112 expands and cools air exhausted from cabin 12 to further cool air passing through second inlet and corresponding second outlet of heat exchanger 114 prior to entering inflow port 14 of cabin 12.
  • Turbine 112 is mechanically coupled to an electric generator 116 via shaft 118 to convert about 145 kw of mechanical power to about 131 kw of electrical power, assuming an efficiency of about 90%.
  • the electrical power is used to supply the power requirements for cabin 12 while excess power is fed to motor 110 to help drive compressor 26 via shaft 34 and gear box 38.
  • a second turbine 120 receives bleed air from bleed port 46 of engine 20.
  • Turbine 120 is mechanically coupled to generator 122 to convert mechanical energy from the turbine to electrical energy for cabin 12 and/or motor 110. Assuming the representative numbers provided in Table 1, turbine 120 provides approximately 200 kw of mechanical power to generator 122 via shaft 124 which is converted to about 180 kw of electrical power. Air exiting the outlet of turbine 120 passes through the second inlet and corresponding second outlet of heat exchanger 114 prior to entering cabin 12 through inflow port 14. Based on the representative numbers provided in Table 1, the effectiveness of the heat exchanger 114 should be about 0.76.
  • heat exchanger 114 is preferably a cross-flow, non-mixing, air-to-air heat exchanger. While not specifically illustrated, this embodiment also includes a water separator placed between heat exchanger 114 and inflow port 14 of cabin 12.
  • the configuration of FIG. 4 indicates a potential fuel savings of about 0.91% SFC for a typical application cruising at 43,000 feet altitude.
  • FIG. 5 another embodiment of an environmental control system according to the present invention is shown.
  • the configuration of FIG. 5 is an alternate all-electric configuration which does not use bleed air for the ECS function. While pre-cooler 48 of FIG. 4 appears schematically identical to pre-cooler 48 of FIGS. 1-4, the pre-cooler of FIG. 5 provides less heat rejection since the bleed air has been eliminated from the ECS function. As such, bleed air through pre-cooler 48 of FIG. 5 is provided only for the anti-ice function, indicated generally by reference numeral 52.
  • Generator 130 converts about 445 kw of mechanical power to about 400 kw of electrical power to supply 165 kw of electrical power to cabin 12 and about 235 kw of electrical power to motor 132.
  • Turbine 70 is mechanically coupled and driven by motor 132 via shaft 134.
  • Turbine 70 is also mechanically coupled to compressor 68 via shaft 72.
  • a first directional valve 136 operates in conjunction with a second directional valve 138 to selectively place turbine 70 in fluid communication with heat exchanger 142. This provides additional cooling in a maximum cooling mode where energy recovery from the outflow air is insufficient to meet the cooling requirements for cabin 12.
  • a mixing valve 140 is provided to supply ram air via path 144 to heat exchanger 142 where necessary.
  • the ram air is combined with air exhausted from the outlet of turbine 66 prior to passing through heat exchanger 142.
  • directional control valves 136 and 138 are actuated to remove turbine 70 from the flow path.
  • heat exchanger 142 is in fluid communication with inflow port 14 of cabin 12 through a water separator (not specifically illustrated).
  • representative numbers for the various states indicated by the hexagons of FIG. 5 are summarized in Table 2 below.
  • FIGS. 6 and 7 another embodiment of an environmental control system according to the present invention is shown.
  • FIG. 6 illustrates the flow path for a maximum cooling mode of operation while
  • FIG. 7 illustrates the flow path for a maximum economy mode of operation.
  • the flow path is altered using one or more switch dampers such as first switch damper 150, second switch damper 152, and third switch damper 154.
  • Representative numbers for pressures and temperatures throughout the system are indicated by the hexagons in the Figures and summarized below in Table 3 for various operating conditions.
  • switch dampers 150, 152 and 154 are used to selectively couple the inlet of turbine 70 either directly to the bleed air from engine 20 or to the second outlet of heat exchanger 160. At the same time, the switch dampers also selectively couple the outlet of turbine 70 to either inflow port 14 of cabin 12 or the second inlet port of heat exchanger 160. Otherwise, the configuration illustrated in FIGS. 6 and 7 is similar to the minimum bleed configuration illustrated in FIG. 1.
  • the switch dampers function to reroute the flows such that, when needed, the bleed and compressed ram flows can be combined and then pre-cooled in heat exchanger 160. Further expansion through turbine 70 brings the temperature down to the 35° F. needed to support the water separation function performed by a water separator (not specifically illustrated).
  • the switch dampers are needed only for the infrequent low-altitude and ground-cooling modes such that they are designed to be low loss devices when in the "straight-through" mode illustrated in FIG. 7.
  • Fan 76 is shown in parallel with a check valve 162 to accommodate those cases where the cabin pressure is insufficient to support the exhaust of conditioned air from cabin 12. Depending upon the particular application, the air driven by fan 76 may bypass turbine 66.
  • This may be accomplished by using adjustable or controllable inlet guide vanes or first-stage stator blades in the turbine.
  • an outflow valve may be provided in parallel to pass a small, variable amount of air to the ambient to accomplish cabin pressure control. Use of the outflow valve should be minimized, however, since any air exhausted through the outflow valve represents lost work.

Landscapes

  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Pulmonology (AREA)
  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Engine Equipment That Uses Special Cycles (AREA)
US08/887,018 1997-07-02 1997-07-02 High efficiency environmental control systems and methods Expired - Lifetime US5967461A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US08/887,018 US5967461A (en) 1997-07-02 1997-07-02 High efficiency environmental control systems and methods
DE69835054T DE69835054T3 (de) 1997-07-02 1998-06-29 Hocheffizientes Klimaregelungssystem
EP98111967A EP0888966B2 (de) 1997-07-02 1998-06-29 Hocheffizientes Klimaregelungssystem

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08/887,018 US5967461A (en) 1997-07-02 1997-07-02 High efficiency environmental control systems and methods

Publications (1)

Publication Number Publication Date
US5967461A true US5967461A (en) 1999-10-19

Family

ID=25390283

Family Applications (1)

Application Number Title Priority Date Filing Date
US08/887,018 Expired - Lifetime US5967461A (en) 1997-07-02 1997-07-02 High efficiency environmental control systems and methods

Country Status (3)

Country Link
US (1) US5967461A (de)
EP (1) EP0888966B2 (de)
DE (1) DE69835054T3 (de)

Cited By (128)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6216981B1 (en) * 1998-03-06 2001-04-17 Rolls-Royce Plc Environmental control system
US6247668B1 (en) * 1999-07-15 2001-06-19 The Boeing Company Auxiliary power and thrust unit
US6305156B1 (en) * 1999-09-03 2001-10-23 Alliedsignal Inc. Integrated bleed air and engine starting system
US6484518B1 (en) * 1999-11-10 2002-11-26 Dassault Aviation Method and system for feeding a cool air inlet of the cabin of an aircraft propelled by at least one jet engine
US6526775B1 (en) * 2001-09-14 2003-03-04 The Boeing Company Electric air conditioning system for an aircraft
US6545610B2 (en) * 1999-05-25 2003-04-08 Kulite Semiconductor Products, Inc. Pressure transducer and switch combination
US6681592B1 (en) * 2001-02-16 2004-01-27 Hamilton Sundstrand Corporation Electrically driven aircraft cabin ventilation and environmental control system
US20040025507A1 (en) * 2002-08-02 2004-02-12 Honeywell International Inc. Turbo compressor for use in OBIGGS application
FR2848647A1 (fr) * 2002-12-14 2004-06-18 Rolls Royce Plc Systeme de commande de conditionnement d'air, notamment pour une cabine d'avion
US20040124308A1 (en) * 2002-12-31 2004-07-01 David Daggett Hybrid solid oxide fuel cell aircraft auxiliary power unit
US20040129835A1 (en) * 2002-10-22 2004-07-08 Atkey Warren A. Electric-based secondary power system architectures for aircraft
US6783114B2 (en) 2001-12-11 2004-08-31 Honeywell International, Inc. Cable assembly and air outflow valve incorporating the same
US20040172963A1 (en) * 2002-04-08 2004-09-09 Honeywell Normalair-Garrett (Holdings) Limited Air conditioning system
US6796131B2 (en) * 2001-09-20 2004-09-28 Honeywell Normalair-Garrett (Holdings) Limited Environmental control system
US6796527B1 (en) * 2001-09-20 2004-09-28 Hamilton Sundstrand Corporation Integrated air turbine driven system for providing aircraft environmental control
US20040195447A1 (en) * 2003-04-03 2004-10-07 Honeywell International Inc. Condensing cycle with energy recovery augmentation
US6817575B1 (en) * 2001-09-20 2004-11-16 Hamilton Sundstrand Corporation Integrated system for providing aircraft environmental control
US6886782B2 (en) * 2001-04-06 2005-05-03 Dassault Aviation System for supplying an aircraft with cool air
US20060010875A1 (en) * 2004-07-16 2006-01-19 Mahoney Timothy D Gas turbine engine bleed air power assist system and method
US20060059927A1 (en) * 2004-09-22 2006-03-23 Thomas Zywiak Electric motor driven supercharger with air cycle air conditioning system
US20060123804A1 (en) * 2002-09-16 2006-06-15 Michael Widegren Device for supplying preconditioned air to an aircraft on the ground
US20060138280A1 (en) * 2004-12-21 2006-06-29 Michael Markwart Arrangement and method for utilizing the heat of waste air for heating the bilge area of aircraft
US20060168968A1 (en) * 2005-02-03 2006-08-03 Edward Zielinski Systems and methods for starting aircraft engines
US20060196216A1 (en) * 2004-09-22 2006-09-07 Bruno Louis J Dual mode condensing cycle
US20060237583A1 (en) * 2005-04-21 2006-10-26 The Boeing Company Combined fuel cell aircraft auxiliary power unit and environmental control system
US20070004326A1 (en) * 2004-04-13 2007-01-04 Joachim Haas System for the preparation of air
US20070175223A1 (en) * 2006-02-02 2007-08-02 General Electric Company Aircraft auxiliary gas turbine engine and method for operating
US20070191988A1 (en) * 2006-02-10 2007-08-16 Aronstam Peter S Apparatus and methods of using card based programmable controllers
US20070234731A1 (en) * 2006-04-05 2007-10-11 General Electric Company System and method for providing air to a compressor of an aircraft auxiliary gas turbine engine
US20080054727A1 (en) * 2006-08-30 2008-03-06 Landmann Wolf S Solid state pressure switch
US20080098747A1 (en) * 2006-10-31 2008-05-01 Karl Edward Sheldon Auxiliary power unit assembly
US20080115837A1 (en) * 2006-11-17 2008-05-22 The Boeing Company Environmental control system, method, and computer program product for controlling the interior environment of a pressurized compartment
US20080283663A1 (en) * 2007-05-17 2008-11-20 The Boeing Company Systems and methods for providing airflow in an aerospace vehicle
US20080314060A1 (en) * 2007-06-20 2008-12-25 The Boeing Company Combined Cabin Air and Heat Exchanger RAM Air Inlets For Aircraft Environmental Control Systems, and Associated Methods of Use
US20090008505A1 (en) * 2004-05-13 2009-01-08 Airbus Deutschland Gmbh Aircraft with a fluid-duct-system
US7481214B2 (en) * 2005-09-19 2009-01-27 The Boeing Company System and method for enriching aircraft cabin air with oxygen from a nitrogen generation system
JP2009503332A (ja) * 2005-07-28 2009-01-29 エアバス フランス 航空機用推進装置とかかる推進装置を少なくとも一基装備した航空機
US20090084122A1 (en) * 2007-10-01 2009-04-02 Carlos Casado Montero Device to control the ventilation and air conditioning of aircraft on the ground
US20090127855A1 (en) * 2007-11-21 2009-05-21 Shander Mark S Electrical systems architecture for an aircraft, and related operating methods
US20090221224A1 (en) * 2006-02-03 2009-09-03 Airbus Deutschland Gmbh Air Conditioning Arrangement For An Aircraft With A Plurality Of Climate Zones That May Be Individually Temperature-Controlled
US20090255277A1 (en) * 2006-10-13 2009-10-15 Airbus Deutschland Gmbh Optimized defrosting regulation of parallel arranged fresh air outlets of air conditioners
US20100051756A1 (en) * 2006-12-12 2010-03-04 Lockheed Martin Corporation System, method, and apparatus for throat corner scoop offtake for mixed compression inlets on aircraft engines
US20100107594A1 (en) * 2008-10-31 2010-05-06 General Electric Company Turbine integrated bleed system and method for a gas turbine engine
US20100172757A1 (en) * 2009-01-07 2010-07-08 Henderson Dale A Indirect drive unit apparatus, system and method
US20110220759A1 (en) * 2008-09-26 2011-09-15 Airbus Operations Gmbh Power distribution system
US20120285184A1 (en) * 2011-05-09 2012-11-15 Honeywell International Inc. Environmental control system with closed loop pressure cycle
US20130040545A1 (en) * 2011-08-11 2013-02-14 Hamilton Sundstrand Corporation Low pressure compressor bleed exit for an aircraft pressurization system
US20130175001A1 (en) * 2012-01-10 2013-07-11 Hamilton Sundstrand Corporation Air recovery system for precooler heat-exchanger
US20130187007A1 (en) * 2012-01-24 2013-07-25 Steve G. Mackin Bleed air systems for use with aircrafts and related methods
US20130333390A1 (en) * 2011-02-21 2013-12-19 Airbus Operations Gmbh Cooling air inlet, engine bleed air system and method for operating a cooling air inlet
WO2014020770A1 (ja) * 2012-08-03 2014-02-06 株式会社島津製作所 タービンコンプレッサー装置、タービンコンプレッサーシステムおよび航空機用換気システム
US8657227B1 (en) 2009-09-11 2014-02-25 The Boeing Company Independent power generation in aircraft
US8738268B2 (en) 2011-03-10 2014-05-27 The Boeing Company Vehicle electrical power management and distribution
US20140144163A1 (en) * 2012-11-23 2014-05-29 Airbus Operations Gmbh Aircraft air conditioning system and method of operating an aircraft air conditioning system
US20140165588A1 (en) * 2012-12-14 2014-06-19 United Technologies Corporation Turbo compressor for bleed air
US20140326135A1 (en) * 2011-11-29 2014-11-06 Eaton Limited On board inert gas generation system
US20150004011A1 (en) * 2013-06-28 2015-01-01 Hamilton Sundstrand Corporation Enhanced motor cooling system and method
US8955794B2 (en) * 2012-01-24 2015-02-17 The Boeing Company Bleed air systems for use with aircrafts and related methods
WO2015026432A1 (en) * 2013-08-21 2015-02-26 Hamilton Sundstrand Corporation Single stage engine bleed
CN104912835A (zh) * 2014-03-10 2015-09-16 波音公司 涡轮压缩机系统、航空器及从航空器发动机提取能量的方法
US20150275758A1 (en) * 2014-04-01 2015-10-01 The Boeing Company Bleed air systems for use with aircraft and related methods
EP2937287A1 (de) * 2014-04-24 2015-10-28 Louis J. Bruno Klimaregelungssystem mit shoestring-kreislauf zur maximierung der effizienz
US20160144965A1 (en) * 2014-11-25 2016-05-26 Hamilton Sundstrand Corporation Environmental control system utilizing cabin air to drive a power turbine of an air cycle machine
US20160169029A1 (en) * 2014-06-27 2016-06-16 United Technologies Corporation Geared turbofan engine with low pressure environmental control system for aircraft
US20160236792A1 (en) * 2010-12-08 2016-08-18 Eaton Limited On board inert gas generation system with rotary positive displacement compressor
US20160257410A1 (en) * 2015-03-04 2016-09-08 Hamilton Sundstrand Corporation Replacement system providing replacement air to an inerting system
US20160311539A1 (en) * 2015-04-24 2016-10-27 Hamilton Sundstrand Corporation Environmental control system mixing cabin discharge air with bleed air during a cycle
US20160332737A1 (en) * 2015-05-11 2016-11-17 United Technologies Corporation Environmental cooling systems for aircraft
US20160340048A1 (en) * 2011-11-28 2016-11-24 Hamilton Sundstrand Corporation Blended flow air cycle system for environmental control
US20160347456A1 (en) * 2015-05-26 2016-12-01 Hamilton Sundstrand Corporation Aircraft environmental control system
US20160355269A1 (en) * 2015-06-08 2016-12-08 Hamilton Sundstrand Corporation Unequal bleed flow
WO2016200915A1 (en) * 2015-06-08 2016-12-15 Hamilton Sundstrand Corporation No primary heat exchanger and bleed air (cabin discharge air) assist
US9580180B2 (en) 2014-03-07 2017-02-28 Honeywell International Inc. Low-pressure bleed air aircraft environmental control system
US20170081031A1 (en) * 2015-09-17 2017-03-23 Airbus Operations Gmbh Ram air channel arrangement and method for operating a ram air channel arrangement
CN106672243A (zh) * 2015-11-11 2017-05-17 空中客车作业有限公司 具有机舱排气涡轮机的飞机空调系统
US9669936B1 (en) * 2012-10-24 2017-06-06 The Boeing Company Aircraft air conditioning systems and methods
US20170267370A1 (en) * 2015-06-25 2017-09-21 Pratt & Whitney Canada Corp. Engine assembly with direct drive of generator
US9784638B1 (en) * 2015-08-31 2017-10-10 The Boeing Company Method and system for diagnoses and prognoses of low temperature limit control valve
US9810158B2 (en) 2014-04-01 2017-11-07 The Boeing Company Bleed air systems for use with aircraft and related methods
EP3249196A1 (de) * 2016-05-26 2017-11-29 Hamilton Sundstrand Corporation Energiefluss eines fortschrittlichen klimaregelungssystems
EP3249195A1 (de) * 2016-05-26 2017-11-29 Hamilton Sundstrand Corporation Energiefluss eines fortschrittlichen klimaregelungssystems
US20170342899A1 (en) * 2016-05-26 2017-11-30 Hamilton Sundstrand Corporation Multiple nozzle configurations for a turbine of an environmental control system
US20170341764A1 (en) * 2016-05-26 2017-11-30 Hamilton Sundstrand Corporation Mixing ram and bleed air in a dual entry turbine system
CN107444658A (zh) * 2016-05-26 2017-12-08 哈米尔顿森德斯特兰德公司 使用双用涡轮机系统来混合排气和冲压空气
US9869190B2 (en) 2014-05-30 2018-01-16 General Electric Company Variable-pitch rotor with remote counterweights
US20180045068A1 (en) * 2016-08-11 2018-02-15 General Electric Company Mechanically driven air vehicle thermal management device
EP3287370A1 (de) * 2016-08-23 2018-02-28 GE Aviation Systems LLC Hybrides verfahren und flugzeug zur vorkühlung eines umweltsteuerungssystems unter verwendung einer stromgenerator-vierradantriebs-turbomaschine
WO2018039289A1 (en) * 2016-08-23 2018-03-01 Ge Aviation Systems Llc Advanced method and aircraft for pre-cooling an environmental control system using a dual compressor four wheel turbo-machine
EP3296543A1 (de) * 2016-09-19 2018-03-21 United Technologies Corporation Gasturbinenmotor mit zwischengekühlter kühlluft und turbinenantrieb
US20180208327A1 (en) * 2017-01-20 2018-07-26 Honeywell Uk Limited Environmental control system for an aeronautic vehicle
US10072510B2 (en) 2014-11-21 2018-09-11 General Electric Company Variable pitch fan for gas turbine engine and method of assembling the same
US20180281977A1 (en) * 2017-04-03 2018-10-04 Hamilton Sundstrand Corporation Turbine-assisted cabin air compressor
US10100744B2 (en) 2015-06-19 2018-10-16 The Boeing Company Aircraft bleed air and engine starter systems and related methods
US10100653B2 (en) 2015-10-08 2018-10-16 General Electric Company Variable pitch fan blade retention system
CN108688816A (zh) * 2017-04-03 2018-10-23 哈米尔顿森德斯特兰德公司 混合第三空气调节组件
US10137993B2 (en) 2016-05-26 2018-11-27 Hamilton Sundstrand Corporation Mixing bleed and ram air using an air cycle machine with two turbines
US10144517B2 (en) 2016-05-26 2018-12-04 Hamilton Sundstrand Corporation Mixing bleed and ram air using a two turbine architecture with an outflow heat exchanger
US20190039738A1 (en) * 2017-08-01 2019-02-07 Honeywell International Inc. Cabin outflow air energy optimized cabin pressurizing system
US10232948B2 (en) 2016-05-26 2019-03-19 Hamilton Sundstrand Corporation Mixing bleed and ram air at a turbine inlet of a compressing device
CN109665106A (zh) * 2017-10-13 2019-04-23 哈米尔顿森德斯特兰德公司 由放出空气和机舱空气驱动的补充组件
US20190185167A1 (en) * 2017-10-05 2019-06-20 Liebherr-Aerospace Toulouse Sas Autonomous aircraft cabin energy recovery module and corresponding method
US20190292985A1 (en) * 2018-03-22 2019-09-26 United Technologies Corporation Intercooled cooling air with combined features
US10451353B2 (en) * 2016-08-05 2019-10-22 Hamilton Sundstrand Corporation Aircraft electronics thermal regulation systems
US10486817B2 (en) 2016-05-26 2019-11-26 Hamilton Sundstrand Corporation Environmental control system with an outflow heat exchanger
US10507928B2 (en) 2017-06-16 2019-12-17 Honeywell International Inc. High efficiency electrically driven environmental control system
US10590842B2 (en) 2015-06-25 2020-03-17 Pratt & Whitney Canada Corp. Compound engine assembly with bleed air
US10597162B2 (en) 2016-05-26 2020-03-24 Hamilton Sundstrand Corporation Mixing bleed and ram air at a turbine inlet
US20200140108A1 (en) * 2016-04-29 2020-05-07 Hamilton Sundstrand Corporation Fuel tank inerting systems for aircraft
US10696417B2 (en) 2015-06-25 2020-06-30 Pratt & Whitney Canada Corp. Auxiliary power unit with excess air recovery
US10710738B2 (en) 2015-06-25 2020-07-14 Pratt & Whitney Canada Corp. Auxiliary power unit with intercooler
US10745136B2 (en) 2013-08-29 2020-08-18 Hamilton Sunstrand Corporation Environmental control system including a compressing device
US10774874B2 (en) * 2018-08-06 2020-09-15 General Electric Company Fluid bearing assembly
US10954865B2 (en) 2018-06-19 2021-03-23 The Boeing Company Pressurized air systems for aircraft and related methods
US10967978B2 (en) * 2014-09-19 2021-04-06 Airbus Operations Gmbh Aircraft air conditioning system and method of operating an aircraft air conditioning system
US10988262B2 (en) 2018-03-14 2021-04-27 Honeywell International Inc. Cabin pressure control system architecture using cabin pressure air for inlet to APU core compressor
US11047237B2 (en) 2016-05-26 2021-06-29 Hamilton Sunstrand Corporation Mixing ram and bleed air in a dual entry turbine system
US20210221521A1 (en) * 2018-11-06 2021-07-22 Ihi Corporation Aircraft air conditioning device
US11260979B2 (en) 2019-05-31 2022-03-01 Hamilton Sundstrand Corporation Aircraft environmental control system
US11273917B2 (en) 2018-05-29 2022-03-15 Honeywell International Inc. Cabin discharge air management system and method for auxiliary power unit
DE102020006235A1 (de) 2020-10-09 2022-04-14 Airbus Defence and Space GmbH Luftleitanordnung für ein Luftfahrzeug mit integriertem Wärmetauscher
EP4005925A1 (de) * 2020-11-30 2022-06-01 Hamilton Sundstrand Corporation Raumluftarchitektur mit einzelluftkreislaufmaschine und hochdruckwasserabscheider
US11396378B2 (en) * 2018-01-24 2022-07-26 Hamilton Sundstrand Corporation ECS dual entry ram inlet plenum
US11465757B2 (en) * 2018-12-06 2022-10-11 The Boeing Company Systems and methods to produce aircraft cabin supply air
US11466904B2 (en) * 2014-11-25 2022-10-11 Hamilton Sundstrand Corporation Environmental control system utilizing cabin air to drive a power turbine of an air cycle machine and utilizing multiple mix points for recirculation air in accordance with pressure mode
US11486315B2 (en) 2020-11-06 2022-11-01 Ge Aviation Systems Llc Combustion engine including turbomachine
US11629870B2 (en) 2020-03-17 2023-04-18 Hamilton Sundstrand Corporation ECS using cabin outflow air as an electricity source
US11674435B2 (en) 2021-06-29 2023-06-13 General Electric Company Levered counterweight feathering system
US11795964B2 (en) 2021-07-16 2023-10-24 General Electric Company Levered counterweight feathering system

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6124646A (en) * 1998-02-11 2000-09-26 Alliedsignal Inc. Aircraft air conditioning system including electric generator for providing AC power having limited frequency range
AU4606200A (en) * 1999-06-09 2000-12-28 Aeroflo (Proprietary) Limited Method and device for mixing gases
DE19935918B4 (de) * 1999-07-30 2006-08-31 Liebherr-Aerospace Lindenberg Gmbh Klimatisierungssystem für Flugzeugkabinen
US6199387B1 (en) 1999-07-30 2001-03-13 Liebherr-Aerospace Lindenberg Gmbh Air-conditioning system for airplane cabin
DE19963280C1 (de) * 1999-12-27 2001-08-23 Liebherr Aerospace Gmbh Klimatisierungssystem für Flugzeugkabinen
US6427471B1 (en) * 2000-02-29 2002-08-06 Shimadzu Corporation Air cycle machine and air conditioning system using the same
US6415595B1 (en) 2000-08-22 2002-07-09 Hamilton Sundstrand Corporation Integrated thermal management and coolant system for an aircraft
US6684660B1 (en) * 2002-08-08 2004-02-03 Hamilton Sundstrand Pneumatic cabin super charger
DE10350541A1 (de) * 2003-10-29 2005-06-16 Liebherr-Aerospace Lindenberg Gmbh Klimatisierungssystem und Verfahren zur Aufbereitung von Luft zur Klimatisierung eines Raumes
FR2911580B1 (fr) * 2007-01-22 2009-02-27 Airbus France Sas Systeme de conditionnement d'air pour aeronef
DE102008019146A1 (de) * 2008-04-16 2009-11-05 Airbus Deutschland Gmbh Enteisungssystem für ein Flugzeug
EP3036118B1 (de) 2013-08-21 2024-01-10 RTX Corporation Umweltkontrollgeneratorsystem und -vorrichtung
JP6343243B2 (ja) * 2015-03-09 2018-06-13 川崎重工業株式会社 航空機用発電装置
GB201513952D0 (en) 2015-08-07 2015-09-23 Rolls Royce Plc Aircraft pneumatic system
CN105966624B (zh) * 2016-05-23 2018-06-22 北京航空航天大学 一种飞机座舱排气增压做功驱动的座舱回风系统
ES2744570T3 (es) * 2016-09-14 2020-02-25 Airbus Operations Sl Aeronave que incorpora un sistema de recuperación de aire de cabina
US10914242B2 (en) * 2017-11-28 2021-02-09 Raytheon Technologies Corporation Complex air supply system for gas turbine engine and associated aircraft
DE102018126921A1 (de) * 2018-10-29 2020-04-30 Airbus Operations Gmbh Flugzeugkälteanlage mit einer motor-unterstützten Kabinenabluftturbine
US11377217B2 (en) 2019-06-11 2022-07-05 Hamilton Sundstrand Corporation Using bleed air to supply outside air to a cabin
US11332252B2 (en) 2019-06-11 2022-05-17 Hamilton Sundstrand Corporation Using bleed air to supply outside air to a cabin

Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2391838A (en) * 1945-12-25 Air conditioning system
US2453923A (en) * 1946-08-20 1948-11-16 Douglas Aircraft Co Inc Aircraft cooling by air turbine means
US2734443A (en) * 1956-02-14 Enclosure air supply system
US2777301A (en) * 1952-06-30 1957-01-15 Garrett Corp All-purpose power and air conditioning system
US2870698A (en) * 1957-04-30 1959-01-27 United Aircraft Corp Recirculating flow aircraft air conditioning system
US3326109A (en) * 1964-03-11 1967-06-20 Bristol Siddeley Engines Ltd Air conditioning systems for aircraft
US3369777A (en) * 1965-01-22 1968-02-20 Westland Aircraft Ltd Aircraft cooling system
US4261416A (en) * 1979-02-23 1981-04-14 The Boeing Company Multimode cabin air conditioning system
GB2076897A (en) * 1980-06-02 1981-12-09 Rockwell International Corp Integrated auxiliary power and environmental control unit
US4419926A (en) * 1980-09-02 1983-12-13 Lockheed Corporation ESC energy recovery system for fuel-efficient aircraft
GB2125956A (en) * 1982-08-26 1984-03-14 United Technologies Corp Multi-zone temperature control in aircraft air cycle refrigeration systems
US4546939A (en) * 1982-05-27 1985-10-15 Lockheed Corporation Energy efficient ECS powered by a variable voltage/variable frequency power system
GB2202933A (en) * 1987-01-16 1988-10-05 Abg Semca Air conditioning pressure cabins in aircraft
US5125597A (en) * 1990-06-01 1992-06-30 General Electric Company Gas turbine engine powered aircraft environmental control system and boundary layer bleed with energy recovery system
US5143329A (en) * 1990-06-01 1992-09-01 General Electric Company Gas turbine engine powered aircraft environmental control system and boundary layer bleed
US5145124A (en) * 1990-07-12 1992-09-08 Allied-Signal Inc. Fluid conditioning system and apparatus
US5299763A (en) * 1991-12-23 1994-04-05 Allied-Signal Inc. Aircraft cabin air conditioning system with improved fresh air supply
US5442905A (en) * 1994-04-08 1995-08-22 Alliedsignal Inc. Integrated power and cooling environmental control system
US5482229A (en) * 1993-06-18 1996-01-09 Deutsche Aerospace Airbus Gmbh Apparatus for generating energy on board of an aircraft
US5490645A (en) * 1993-12-09 1996-02-13 Allied-Signal Inc. Fully integrated environmental and secondary power system
US5813630A (en) * 1996-09-27 1998-09-29 Mcdonnell Douglas Corporation Multi-mode secondary power unit

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4312191A (en) * 1980-02-15 1982-01-26 Sundstrand Corporation Environmental control system for aircraft with improved efficiency
US5461882A (en) 1994-07-22 1995-10-31 United Technologies Corporation Regenerative condensing cycle
GB9508043D0 (en) 1995-04-20 1995-06-07 British Aerospace Environmental control system

Patent Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2734443A (en) * 1956-02-14 Enclosure air supply system
US2391838A (en) * 1945-12-25 Air conditioning system
US2453923A (en) * 1946-08-20 1948-11-16 Douglas Aircraft Co Inc Aircraft cooling by air turbine means
US2777301A (en) * 1952-06-30 1957-01-15 Garrett Corp All-purpose power and air conditioning system
US2870698A (en) * 1957-04-30 1959-01-27 United Aircraft Corp Recirculating flow aircraft air conditioning system
US3326109A (en) * 1964-03-11 1967-06-20 Bristol Siddeley Engines Ltd Air conditioning systems for aircraft
US3369777A (en) * 1965-01-22 1968-02-20 Westland Aircraft Ltd Aircraft cooling system
US4261416A (en) * 1979-02-23 1981-04-14 The Boeing Company Multimode cabin air conditioning system
GB2076897A (en) * 1980-06-02 1981-12-09 Rockwell International Corp Integrated auxiliary power and environmental control unit
US4419926A (en) * 1980-09-02 1983-12-13 Lockheed Corporation ESC energy recovery system for fuel-efficient aircraft
US4546939A (en) * 1982-05-27 1985-10-15 Lockheed Corporation Energy efficient ECS powered by a variable voltage/variable frequency power system
GB2125956A (en) * 1982-08-26 1984-03-14 United Technologies Corp Multi-zone temperature control in aircraft air cycle refrigeration systems
GB2202933A (en) * 1987-01-16 1988-10-05 Abg Semca Air conditioning pressure cabins in aircraft
US5125597A (en) * 1990-06-01 1992-06-30 General Electric Company Gas turbine engine powered aircraft environmental control system and boundary layer bleed with energy recovery system
US5143329A (en) * 1990-06-01 1992-09-01 General Electric Company Gas turbine engine powered aircraft environmental control system and boundary layer bleed
US5145124A (en) * 1990-07-12 1992-09-08 Allied-Signal Inc. Fluid conditioning system and apparatus
US5299763A (en) * 1991-12-23 1994-04-05 Allied-Signal Inc. Aircraft cabin air conditioning system with improved fresh air supply
US5482229A (en) * 1993-06-18 1996-01-09 Deutsche Aerospace Airbus Gmbh Apparatus for generating energy on board of an aircraft
US5490645A (en) * 1993-12-09 1996-02-13 Allied-Signal Inc. Fully integrated environmental and secondary power system
US5442905A (en) * 1994-04-08 1995-08-22 Alliedsignal Inc. Integrated power and cooling environmental control system
US5813630A (en) * 1996-09-27 1998-09-29 Mcdonnell Douglas Corporation Multi-mode secondary power unit

Cited By (253)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6216981B1 (en) * 1998-03-06 2001-04-17 Rolls-Royce Plc Environmental control system
US6545610B2 (en) * 1999-05-25 2003-04-08 Kulite Semiconductor Products, Inc. Pressure transducer and switch combination
US6247668B1 (en) * 1999-07-15 2001-06-19 The Boeing Company Auxiliary power and thrust unit
US6305156B1 (en) * 1999-09-03 2001-10-23 Alliedsignal Inc. Integrated bleed air and engine starting system
US6484518B1 (en) * 1999-11-10 2002-11-26 Dassault Aviation Method and system for feeding a cool air inlet of the cabin of an aircraft propelled by at least one jet engine
US6681592B1 (en) * 2001-02-16 2004-01-27 Hamilton Sundstrand Corporation Electrically driven aircraft cabin ventilation and environmental control system
US6928832B2 (en) 2001-02-16 2005-08-16 Hamilton Sunstrand Corporation Electrically driven aircraft cabin ventilation and environmental control system
US20040060317A1 (en) * 2001-02-16 2004-04-01 Lents Charles E. Electrically driven aircraft cabin ventilation and environmental control system
US6886782B2 (en) * 2001-04-06 2005-05-03 Dassault Aviation System for supplying an aircraft with cool air
US6526775B1 (en) * 2001-09-14 2003-03-04 The Boeing Company Electric air conditioning system for an aircraft
US6796131B2 (en) * 2001-09-20 2004-09-28 Honeywell Normalair-Garrett (Holdings) Limited Environmental control system
US6796527B1 (en) * 2001-09-20 2004-09-28 Hamilton Sundstrand Corporation Integrated air turbine driven system for providing aircraft environmental control
US6817575B1 (en) * 2001-09-20 2004-11-16 Hamilton Sundstrand Corporation Integrated system for providing aircraft environmental control
US6783114B2 (en) 2001-12-11 2004-08-31 Honeywell International, Inc. Cable assembly and air outflow valve incorporating the same
US7040112B2 (en) * 2002-04-08 2006-05-09 Honewell Normalair-Garrett (Holdings) Limited Air conditioning system
US20040172963A1 (en) * 2002-04-08 2004-09-09 Honeywell Normalair-Garrett (Holdings) Limited Air conditioning system
US20040025507A1 (en) * 2002-08-02 2004-02-12 Honeywell International Inc. Turbo compressor for use in OBIGGS application
US20060123804A1 (en) * 2002-09-16 2006-06-15 Michael Widegren Device for supplying preconditioned air to an aircraft on the ground
US7322203B2 (en) * 2002-09-16 2008-01-29 Ipalco B.V. Device for supplying preconditioned air to an aircraft on the ground
US20060102790A1 (en) * 2002-10-22 2006-05-18 Atkey Warren A Electric-based secondary power system architectures for aircraft
US20070284480A1 (en) * 2002-10-22 2007-12-13 The Boeing Company Electric-based secondary power system architectures for aircraft
US20070267540A1 (en) * 2002-10-22 2007-11-22 Atkey Warren A Electric-based secondary power system architectures for aircraft
US20040129835A1 (en) * 2002-10-22 2004-07-08 Atkey Warren A. Electric-based secondary power system architectures for aircraft
US7210653B2 (en) 2002-10-22 2007-05-01 The Boeing Company Electric-based secondary power system architectures for aircraft
US7207521B2 (en) 2002-10-22 2007-04-24 The Boeing Company Electric-based secondary power system architectures for aircraft
US7950606B2 (en) 2002-10-22 2011-05-31 The Boeing Company Electric-based secondary power system architectures for aircraft
FR2848647A1 (fr) * 2002-12-14 2004-06-18 Rolls Royce Plc Systeme de commande de conditionnement d'air, notamment pour une cabine d'avion
US20040195448A1 (en) * 2002-12-14 2004-10-07 Flatman Richard J. Environmental control system
US20040124308A1 (en) * 2002-12-31 2004-07-01 David Daggett Hybrid solid oxide fuel cell aircraft auxiliary power unit
US6834831B2 (en) * 2002-12-31 2004-12-28 The Boeing Company Hybrid solid oxide fuel cell aircraft auxiliary power unit
US6848261B2 (en) 2003-04-03 2005-02-01 Honeywell International Inc. Condensing cycle with energy recovery augmentation
US20040195447A1 (en) * 2003-04-03 2004-10-07 Honeywell International Inc. Condensing cycle with energy recovery augmentation
US7410526B2 (en) * 2004-04-13 2008-08-12 Liebherr-Aerospace Lindenberg Gmbh System for the preparation of air
US20070004326A1 (en) * 2004-04-13 2007-01-04 Joachim Haas System for the preparation of air
US7988102B2 (en) * 2004-05-13 2011-08-02 Airbus Deutschland Gmbh Aircraft with a fluid-duct-system
US20090008505A1 (en) * 2004-05-13 2009-01-08 Airbus Deutschland Gmbh Aircraft with a fluid-duct-system
US20060010875A1 (en) * 2004-07-16 2006-01-19 Mahoney Timothy D Gas turbine engine bleed air power assist system and method
US7246482B2 (en) 2004-07-16 2007-07-24 Honeywell International, Inc. Gas turbine engine bleed air power assist system and method
US20060059927A1 (en) * 2004-09-22 2006-03-23 Thomas Zywiak Electric motor driven supercharger with air cycle air conditioning system
US7334423B2 (en) * 2004-09-22 2008-02-26 Hamilton Sundstrand Corporation Dual mode condensing cycle
US20060196216A1 (en) * 2004-09-22 2006-09-07 Bruno Louis J Dual mode condensing cycle
US7322202B2 (en) * 2004-09-22 2008-01-29 Hamilton Sundstrand Corporation Electric motor driven supercharger with air cycle air conditioning system
US20060138280A1 (en) * 2004-12-21 2006-06-29 Michael Markwart Arrangement and method for utilizing the heat of waste air for heating the bilge area of aircraft
US20110192565A1 (en) * 2004-12-21 2011-08-11 Airbus Deutschland Gmbh Arrangement and method for utilizing the heat of waste air for heating the bilge area of aircraft
US8137169B2 (en) * 2004-12-21 2012-03-20 Airbus Operations Gmbh Arrangement and method for utilizing the heat of waste air for heating the bilge area of aircraft
US7980928B2 (en) * 2004-12-21 2011-07-19 Airbus Deutschland Gmbh Arrangement and method for utilizing the heat of waste air for heating the bilge area of aircraft
US20060168968A1 (en) * 2005-02-03 2006-08-03 Edward Zielinski Systems and methods for starting aircraft engines
US7513119B2 (en) 2005-02-03 2009-04-07 The Boeing Company Systems and methods for starting aircraft engines
US8016228B2 (en) 2005-04-21 2011-09-13 The Boeing Company Combined fuel cell aircraft auxiliary power unit and environmental control system
US20090305092A1 (en) * 2005-04-21 2009-12-10 The Boeing Company Combined fuel cell aircraft auxiliary power unit and environmental control system
US7380749B2 (en) 2005-04-21 2008-06-03 The Boeing Company Combined fuel cell aircraft auxiliary power unit and environmental control system
US20060237583A1 (en) * 2005-04-21 2006-10-26 The Boeing Company Combined fuel cell aircraft auxiliary power unit and environmental control system
JP2009503332A (ja) * 2005-07-28 2009-01-29 エアバス フランス 航空機用推進装置とかかる推進装置を少なくとも一基装備した航空機
JP4887364B2 (ja) * 2005-07-28 2012-02-29 エルビュス オペラシオン (エス.アー.エス.) 航空機用推進装置とかかる推進装置を少なくとも一基装備した航空機
US7481214B2 (en) * 2005-09-19 2009-01-27 The Boeing Company System and method for enriching aircraft cabin air with oxygen from a nitrogen generation system
US20070175223A1 (en) * 2006-02-02 2007-08-02 General Electric Company Aircraft auxiliary gas turbine engine and method for operating
US7721554B2 (en) * 2006-02-02 2010-05-25 General Electric Company Aircraft auxiliary gas turbine engine and method for operating
US8435103B2 (en) * 2006-02-03 2013-05-07 Airbus Deutschland Gmbh Air conditioning arrangement for an aircraft with a plurality of climate zones that may be individually temperature-controlled
US20090221224A1 (en) * 2006-02-03 2009-09-03 Airbus Deutschland Gmbh Air Conditioning Arrangement For An Aircraft With A Plurality Of Climate Zones That May Be Individually Temperature-Controlled
US20090187710A1 (en) * 2006-02-10 2009-07-23 Aronstam Peter S Apparatus and methods of using card based programmable controllers
US20070191988A1 (en) * 2006-02-10 2007-08-16 Aronstam Peter S Apparatus and methods of using card based programmable controllers
CN101050726B (zh) * 2006-04-05 2012-06-27 通用电气公司 给飞机辅助燃气轮机的压缩机提供空气的系统和方法
US20070234731A1 (en) * 2006-04-05 2007-10-11 General Electric Company System and method for providing air to a compressor of an aircraft auxiliary gas turbine engine
US7673459B2 (en) * 2006-04-05 2010-03-09 General Electric Company System and method for providing air to a compressor of an aircraft auxiliary gas turbine engine
US20080054727A1 (en) * 2006-08-30 2008-03-06 Landmann Wolf S Solid state pressure switch
US7595570B2 (en) 2006-08-30 2009-09-29 Kulite Semiconductor Products, Inc. Solid state pressure switch
US20090255277A1 (en) * 2006-10-13 2009-10-15 Airbus Deutschland Gmbh Optimized defrosting regulation of parallel arranged fresh air outlets of air conditioners
US8480028B2 (en) * 2006-10-13 2013-07-09 Airbus Deutschland Gmbh Optimized defrosting regulation of parallel arranged fresh air outlets of air conditioners
US20080098747A1 (en) * 2006-10-31 2008-05-01 Karl Edward Sheldon Auxiliary power unit assembly
US7707838B2 (en) * 2006-10-31 2010-05-04 General Electric Company Auxiliary power unit assembly
US20080115837A1 (en) * 2006-11-17 2008-05-22 The Boeing Company Environmental control system, method, and computer program product for controlling the interior environment of a pressurized compartment
US7778735B2 (en) * 2006-11-17 2010-08-17 The Boeing Company Environmental control system, method, and computer program product for controlling the interior environment of a pressurized compartment
US7690595B2 (en) * 2006-12-12 2010-04-06 Lockheed Martin Corporation System, method, and apparatus for throat corner scoop offtake for mixed compression inlets on aircraft engines
US20100051756A1 (en) * 2006-12-12 2010-03-04 Lockheed Martin Corporation System, method, and apparatus for throat corner scoop offtake for mixed compression inlets on aircraft engines
US7871038B2 (en) * 2007-05-17 2011-01-18 The Boeing Company Systems and methods for providing airflow in an aerospace vehicle
US20080283663A1 (en) * 2007-05-17 2008-11-20 The Boeing Company Systems and methods for providing airflow in an aerospace vehicle
US7849702B2 (en) * 2007-06-20 2010-12-14 The Boeing Company Combined cabin air and heat exchanger RAM air inlets for aircraft environmental control systems, and associated methods of use
US20080314060A1 (en) * 2007-06-20 2008-12-25 The Boeing Company Combined Cabin Air and Heat Exchanger RAM Air Inlets For Aircraft Environmental Control Systems, and Associated Methods of Use
US8042349B2 (en) 2007-10-01 2011-10-25 Airbus Operations, S.L. Device to control the ventilation and air conditioning of aircraft on the ground
ES2349206A1 (es) * 2007-10-01 2010-12-29 Airbus Operations, S.L. Dispositivo de control de la demanda de ventilacion y acondicionamiento de aire de una aeronave en tierra.
US20090084122A1 (en) * 2007-10-01 2009-04-02 Carlos Casado Montero Device to control the ventilation and air conditioning of aircraft on the ground
US7687927B2 (en) 2007-11-21 2010-03-30 The Boeing Company Electrical systems architecture for an aircraft, and related operating methods
US20090127855A1 (en) * 2007-11-21 2009-05-21 Shander Mark S Electrical systems architecture for an aircraft, and related operating methods
US8672263B2 (en) * 2008-09-26 2014-03-18 Airbus Operations Gmbh Power distribution system
US20110220759A1 (en) * 2008-09-26 2011-09-15 Airbus Operations Gmbh Power distribution system
US20100107594A1 (en) * 2008-10-31 2010-05-06 General Electric Company Turbine integrated bleed system and method for a gas turbine engine
US20100172757A1 (en) * 2009-01-07 2010-07-08 Henderson Dale A Indirect drive unit apparatus, system and method
US8950703B2 (en) 2009-09-11 2015-02-10 The Boeing Company Independent power generation in aircraft
US8657227B1 (en) 2009-09-11 2014-02-25 The Boeing Company Independent power generation in aircraft
US20160236792A1 (en) * 2010-12-08 2016-08-18 Eaton Limited On board inert gas generation system with rotary positive displacement compressor
US20130333390A1 (en) * 2011-02-21 2013-12-19 Airbus Operations Gmbh Cooling air inlet, engine bleed air system and method for operating a cooling air inlet
US8738268B2 (en) 2011-03-10 2014-05-27 The Boeing Company Vehicle electrical power management and distribution
US20120285184A1 (en) * 2011-05-09 2012-11-15 Honeywell International Inc. Environmental control system with closed loop pressure cycle
US9169024B2 (en) * 2011-05-09 2015-10-27 Honeywell International Inc. Environmental control system with closed loop pressure cycle
US20130040545A1 (en) * 2011-08-11 2013-02-14 Hamilton Sundstrand Corporation Low pressure compressor bleed exit for an aircraft pressurization system
US20160340048A1 (en) * 2011-11-28 2016-11-24 Hamilton Sundstrand Corporation Blended flow air cycle system for environmental control
US10669032B2 (en) 2011-11-28 2020-06-02 Hamilton Sunstrand Corporation Blended flow air cycle system for environmental control
US10059458B2 (en) * 2011-11-28 2018-08-28 Hamilton Sundstrand Corporation Blended flow air cycle system for environmental control
US20140326135A1 (en) * 2011-11-29 2014-11-06 Eaton Limited On board inert gas generation system
US20130175001A1 (en) * 2012-01-10 2013-07-11 Hamilton Sundstrand Corporation Air recovery system for precooler heat-exchanger
US9109514B2 (en) * 2012-01-10 2015-08-18 Hamilton Sundstrand Corporation Air recovery system for precooler heat-exchanger
US8955794B2 (en) * 2012-01-24 2015-02-17 The Boeing Company Bleed air systems for use with aircrafts and related methods
US8967528B2 (en) * 2012-01-24 2015-03-03 The Boeing Company Bleed air systems for use with aircrafts and related methods
US20150176501A1 (en) * 2012-01-24 2015-06-25 The Boeing Company Bleed air systems for use with aircrafts and related methods
US9765700B2 (en) * 2012-01-24 2017-09-19 The Boeing Company Bleed air systems for use with aircrafts and related methods
US20130187007A1 (en) * 2012-01-24 2013-07-25 Steve G. Mackin Bleed air systems for use with aircrafts and related methods
WO2014020770A1 (ja) * 2012-08-03 2014-02-06 株式会社島津製作所 タービンコンプレッサー装置、タービンコンプレッサーシステムおよび航空機用換気システム
US9669936B1 (en) * 2012-10-24 2017-06-06 The Boeing Company Aircraft air conditioning systems and methods
US20140144163A1 (en) * 2012-11-23 2014-05-29 Airbus Operations Gmbh Aircraft air conditioning system and method of operating an aircraft air conditioning system
US10563592B2 (en) * 2012-12-14 2020-02-18 United Technologies Corporation Turbo compressor for bleed air
US20140165588A1 (en) * 2012-12-14 2014-06-19 United Technologies Corporation Turbo compressor for bleed air
US10184494B2 (en) * 2013-06-28 2019-01-22 Hamilton Sundstrand Corporation Enhance motor cooling system and method
US20150004011A1 (en) * 2013-06-28 2015-01-01 Hamilton Sundstrand Corporation Enhanced motor cooling system and method
US11156233B2 (en) 2013-06-28 2021-10-26 Hamilton Sundstrand Corporation Enhanced motor cooling system and method
US11391299B2 (en) 2013-06-28 2022-07-19 Hamilton Sundstrand Corporation Enhanced motor cooling system and method
US11959499B2 (en) * 2013-06-28 2024-04-16 Hamilton Sundstrand Corporation Enhanced motor cooling system and method
EP3036161A4 (de) * 2013-08-21 2016-08-03 Hamilton Sundstrand Corp Einstufiger motorentlüftung
EP3473545A1 (de) * 2013-08-21 2019-04-24 Hamilton Sundstrand Corporation Einstufige motorentlüftung
US20160107754A1 (en) * 2013-08-21 2016-04-21 Hamilton Sundstrand Corporation Single stage engine bleed
US10071806B2 (en) * 2013-08-21 2018-09-11 United Technologies Corporation Single stage engine bleed
WO2015026432A1 (en) * 2013-08-21 2015-02-26 Hamilton Sundstrand Corporation Single stage engine bleed
US10745136B2 (en) 2013-08-29 2020-08-18 Hamilton Sunstrand Corporation Environmental control system including a compressing device
US9580180B2 (en) 2014-03-07 2017-02-28 Honeywell International Inc. Low-pressure bleed air aircraft environmental control system
EP2918497A1 (de) * 2014-03-10 2015-09-16 The Boeing Company Turboladersystem und Verfahren zur Extraktion von Energie aus einem Flugzeugtriebwerk
RU2678234C2 (ru) * 2014-03-10 2019-01-24 Зе Боинг Компани Турбокомпрессорная система и способ извлечения энергии из двигателя воздушного летательного аппарата
CN104912835B (zh) * 2014-03-10 2020-01-31 波音公司 涡轮压缩机系统、航空器及从航空器发动机提取能量的方法
CN104912835A (zh) * 2014-03-10 2015-09-16 波音公司 涡轮压缩机系统、航空器及从航空器发动机提取能量的方法
US9656756B2 (en) 2014-03-10 2017-05-23 The Boeing Company Turbo-compressor system and method for extracting energy from an aircraft engine
US10550770B2 (en) * 2014-04-01 2020-02-04 The Boeing Company Bleed air systems for use with aircraft and related methods
US9810158B2 (en) 2014-04-01 2017-11-07 The Boeing Company Bleed air systems for use with aircraft and related methods
US20150275758A1 (en) * 2014-04-01 2015-10-01 The Boeing Company Bleed air systems for use with aircraft and related methods
US10054051B2 (en) * 2014-04-01 2018-08-21 The Boeing Company Bleed air systems for use with aircraft and related methods
EP2937287A1 (de) * 2014-04-24 2015-10-28 Louis J. Bruno Klimaregelungssystem mit shoestring-kreislauf zur maximierung der effizienz
US9869190B2 (en) 2014-05-30 2018-01-16 General Electric Company Variable-pitch rotor with remote counterweights
US20160169029A1 (en) * 2014-06-27 2016-06-16 United Technologies Corporation Geared turbofan engine with low pressure environmental control system for aircraft
US9915165B2 (en) * 2014-06-27 2018-03-13 United Technologies Corporation Geared turbofan engine with low pressure environmental control system for aircraft
US10967978B2 (en) * 2014-09-19 2021-04-06 Airbus Operations Gmbh Aircraft air conditioning system and method of operating an aircraft air conditioning system
US10072510B2 (en) 2014-11-21 2018-09-11 General Electric Company Variable pitch fan for gas turbine engine and method of assembling the same
US20160144965A1 (en) * 2014-11-25 2016-05-26 Hamilton Sundstrand Corporation Environmental control system utilizing cabin air to drive a power turbine of an air cycle machine
CN105620756B (zh) * 2014-11-25 2020-07-17 哈米尔顿森德斯特兰德公司 利用座舱空气驱动空气循环机的动力涡轮的环境控制系统
CN105620756A (zh) * 2014-11-25 2016-06-01 哈米尔顿森德斯特兰德公司 利用座舱空气驱动空气循环机的动力涡轮的环境控制系统
US10549860B2 (en) * 2014-11-25 2020-02-04 Hamilton Sundstrand Corporation Environmental control system utilizing cabin air to drive a power turbine of an air cycle machine
US11466904B2 (en) * 2014-11-25 2022-10-11 Hamilton Sundstrand Corporation Environmental control system utilizing cabin air to drive a power turbine of an air cycle machine and utilizing multiple mix points for recirculation air in accordance with pressure mode
EP3025962A1 (de) * 2014-11-25 2016-06-01 Hamilton Sundstrand Corporation Umgebungssteuerungssystem unter verwendung von kabinenluft zum antrieb einer nutzturbine einer luftkreislaufmaschine
US9994323B2 (en) * 2015-03-04 2018-06-12 Hamilton Sundstrand Corporation Replacement system providing replacement air to an inerting system
US20160257410A1 (en) * 2015-03-04 2016-09-08 Hamilton Sundstrand Corporation Replacement system providing replacement air to an inerting system
US9840333B2 (en) * 2015-04-24 2017-12-12 Hamilton Sundstrand Corporation Environmental control system mixing cabin discharge air with bleed air during a cycle
US20160311539A1 (en) * 2015-04-24 2016-10-27 Hamilton Sundstrand Corporation Environmental control system mixing cabin discharge air with bleed air during a cycle
US10494106B2 (en) * 2015-05-11 2019-12-03 United Technologies Corporation Environmental cooling systems for aircraft
US20160332737A1 (en) * 2015-05-11 2016-11-17 United Technologies Corporation Environmental cooling systems for aircraft
US10669031B2 (en) 2015-05-11 2020-06-02 Raytheon Technologies Corporation Environmental cooling systems for aircraft
US20160347456A1 (en) * 2015-05-26 2016-12-01 Hamilton Sundstrand Corporation Aircraft environmental control system
US10160547B2 (en) * 2015-05-26 2018-12-25 Hamilton Sundstrand Corporation Aircraft environmental control system
US20160355269A1 (en) * 2015-06-08 2016-12-08 Hamilton Sundstrand Corporation Unequal bleed flow
WO2016200915A1 (en) * 2015-06-08 2016-12-15 Hamilton Sundstrand Corporation No primary heat exchanger and bleed air (cabin discharge air) assist
EP3303134A4 (de) * 2015-06-08 2019-06-19 Hamilton Sundstrand Corporation Unterstützung der zapfluft (kabinenabluft) ohne primärwärmetauscher
US10814988B2 (en) * 2015-06-08 2020-10-27 Hamilton Sunstrand Corporation Unequal bleed flow
CN107690407A (zh) * 2015-06-08 2018-02-13 哈米尔顿森德斯特兰德公司 无初级换热器和排气(机舱放气)辅助
US10035602B2 (en) 2015-06-08 2018-07-31 Hamilton Sundstrand Corporation No primary heat exchanger and bleed air (cabin discharge air) assist
US10100744B2 (en) 2015-06-19 2018-10-16 The Boeing Company Aircraft bleed air and engine starter systems and related methods
US10710738B2 (en) 2015-06-25 2020-07-14 Pratt & Whitney Canada Corp. Auxiliary power unit with intercooler
US11584539B2 (en) 2015-06-25 2023-02-21 Pratt & Whitney Canada Corp. Auxiliary power unit with intercooler
US20170267370A1 (en) * 2015-06-25 2017-09-21 Pratt & Whitney Canada Corp. Engine assembly with direct drive of generator
US10696417B2 (en) 2015-06-25 2020-06-30 Pratt & Whitney Canada Corp. Auxiliary power unit with excess air recovery
US9994332B2 (en) * 2015-06-25 2018-06-12 Pratt & Whitney Canada Corp. Engine assembly with direct drive of generator
US10590842B2 (en) 2015-06-25 2020-03-17 Pratt & Whitney Canada Corp. Compound engine assembly with bleed air
US9784638B1 (en) * 2015-08-31 2017-10-10 The Boeing Company Method and system for diagnoses and prognoses of low temperature limit control valve
US10377495B2 (en) * 2015-09-17 2019-08-13 Airbus Operations Gmbh Ram air channel arrangement and method for operating a ram air channel arrangement
US20170081031A1 (en) * 2015-09-17 2017-03-23 Airbus Operations Gmbh Ram air channel arrangement and method for operating a ram air channel arrangement
US10100653B2 (en) 2015-10-08 2018-10-16 General Electric Company Variable pitch fan blade retention system
US10543925B2 (en) 2015-11-11 2020-01-28 Airbus Operations Gmbh Aircraft air conditioning system with a cabin exhaust air turbine
CN106672243A (zh) * 2015-11-11 2017-05-17 空中客车作业有限公司 具有机舱排气涡轮机的飞机空调系统
US11518523B2 (en) 2015-11-11 2022-12-06 Airbus Operations Gmbh Aircraft air conditioning system with a cabin exhaust air turbine
US11542017B2 (en) 2015-11-11 2023-01-03 Airbus Operations Gmbh Aircraft air conditioning system with a cabin exhaust air turbine
CN106672243B (zh) * 2015-11-11 2019-09-13 空中客车作业有限公司 具有机舱排气涡轮机的飞机空调系统
US20200140108A1 (en) * 2016-04-29 2020-05-07 Hamilton Sundstrand Corporation Fuel tank inerting systems for aircraft
US11511867B2 (en) * 2016-05-26 2022-11-29 Hamilton Sundstrand Corporation Mixing ram and bleed air in a dual entry turbine system
US10597162B2 (en) 2016-05-26 2020-03-24 Hamilton Sundstrand Corporation Mixing bleed and ram air at a turbine inlet
US20210047044A1 (en) * 2016-05-26 2021-02-18 Hamilton Sundstrand Corporation Energy flow of an advanced environmental control system
US10870490B2 (en) 2016-05-26 2020-12-22 Hamilton Sunstrand Corporation Energy flow
EP3825531A1 (de) 2016-05-26 2021-05-26 Hamilton Sundstrand Corporation Energiefluss eines fortschrittlichen klimaregelungssystems
US10486817B2 (en) 2016-05-26 2019-11-26 Hamilton Sundstrand Corporation Environmental control system with an outflow heat exchanger
CN107434044A (zh) * 2016-05-26 2017-12-05 哈米尔顿森德斯特兰德公司 先进环境控制系统的能量流动
CN107444658B (zh) * 2016-05-26 2022-05-13 哈米尔顿森德斯特兰德公司 使用双用涡轮机系统来混合排气和冲压空气
US11981440B2 (en) * 2016-05-26 2024-05-14 Hamilton Sundstrand Corporation Energy flow of an advanced environmental control system
CN107434046B (zh) * 2016-05-26 2022-07-26 哈米尔顿森德斯特兰德公司 先进环境控制系统的能量流动
US10773807B2 (en) 2016-05-26 2020-09-15 Hamilton Sunstrand Corporation Energy flow of an advanced environmental control system
US10232948B2 (en) 2016-05-26 2019-03-19 Hamilton Sundstrand Corporation Mixing bleed and ram air at a turbine inlet of a compressing device
CN107434046A (zh) * 2016-05-26 2017-12-05 哈米尔顿森德斯特兰德公司 先进环境控制系统的能量流动
CN107444658A (zh) * 2016-05-26 2017-12-08 哈米尔顿森德斯特兰德公司 使用双用涡轮机系统来混合排气和冲压空气
US20170341764A1 (en) * 2016-05-26 2017-11-30 Hamilton Sundstrand Corporation Mixing ram and bleed air in a dual entry turbine system
CN107434044B (zh) * 2016-05-26 2021-12-28 哈米尔顿森德斯特兰德公司 先进环境控制系统的能量流动
US10144517B2 (en) 2016-05-26 2018-12-04 Hamilton Sundstrand Corporation Mixing bleed and ram air using a two turbine architecture with an outflow heat exchanger
US11047237B2 (en) 2016-05-26 2021-06-29 Hamilton Sunstrand Corporation Mixing ram and bleed air in a dual entry turbine system
US10604263B2 (en) 2016-05-26 2020-03-31 Hamilton Sundstrand Corporation Mixing bleed and ram air using a dual use turbine system
US10137993B2 (en) 2016-05-26 2018-11-27 Hamilton Sundstrand Corporation Mixing bleed and ram air using an air cycle machine with two turbines
US11506121B2 (en) * 2016-05-26 2022-11-22 Hamilton Sundstrand Corporation Multiple nozzle configurations for a turbine of an environmental control system
US10953992B2 (en) 2016-05-26 2021-03-23 Hamilton Sundstrand Corporation Mixing bleed and ram air using an air cycle machine with two turbines
US20170342899A1 (en) * 2016-05-26 2017-11-30 Hamilton Sundstrand Corporation Multiple nozzle configurations for a turbine of an environmental control system
EP3249196A1 (de) * 2016-05-26 2017-11-29 Hamilton Sundstrand Corporation Energiefluss eines fortschrittlichen klimaregelungssystems
EP3249195A1 (de) * 2016-05-26 2017-11-29 Hamilton Sundstrand Corporation Energiefluss eines fortschrittlichen klimaregelungssystems
US11262133B2 (en) 2016-08-05 2022-03-01 Hamilton Sundstrand Corporation Aircraft electronics thermal regulation systems
US10451353B2 (en) * 2016-08-05 2019-10-22 Hamilton Sundstrand Corporation Aircraft electronics thermal regulation systems
US20180045068A1 (en) * 2016-08-11 2018-02-15 General Electric Company Mechanically driven air vehicle thermal management device
US11203949B2 (en) * 2016-08-11 2021-12-21 General Electric Company Mechanically driven air vehicle thermal management device
CN109563779A (zh) * 2016-08-11 2019-04-02 通用电气公司 机械驱动空气载具热管理装置
WO2018039289A1 (en) * 2016-08-23 2018-03-01 Ge Aviation Systems Llc Advanced method and aircraft for pre-cooling an environmental control system using a dual compressor four wheel turbo-machine
US10358221B2 (en) * 2016-08-23 2019-07-23 Ge Aviation Systems Llc Hybrid method and aircraft for pre-cooling an environmental control system using a power generator four wheel turbo-machine
JP2019528213A (ja) * 2016-08-23 2019-10-10 ジーイー・アビエイション・システムズ・エルエルシー 二重圧縮機4ホイールターボマシンを用いた環境制御システムの改善された予冷方法および航空機
EP3287370A1 (de) * 2016-08-23 2018-02-28 GE Aviation Systems LLC Hybrides verfahren und flugzeug zur vorkühlung eines umweltsteuerungssystems unter verwendung einer stromgenerator-vierradantriebs-turbomaschine
US11377216B2 (en) 2016-08-23 2022-07-05 Ge Aviation Systems Llc Advanced method and aircraft for pre-cooling an environmental control system using a dual compressor four wheel turbo-machine
US11236675B2 (en) 2016-09-19 2022-02-01 Raytheon Technologies Corporation Gas turbine engine with intercooled cooling air and turbine drive
EP3296543A1 (de) * 2016-09-19 2018-03-21 United Technologies Corporation Gasturbinenmotor mit zwischengekühlter kühlluft und turbinenantrieb
EP3581777A1 (de) * 2016-09-19 2019-12-18 United Technologies Corporation Gasturbinenmotor mit zwischengekühlter kühlluft und turbinenantrieb
US10669940B2 (en) 2016-09-19 2020-06-02 Raytheon Technologies Corporation Gas turbine engine with intercooled cooling air and turbine drive
US20180208327A1 (en) * 2017-01-20 2018-07-26 Honeywell Uk Limited Environmental control system for an aeronautic vehicle
US10569885B2 (en) * 2017-01-20 2020-02-25 Honeywell Uk Limited Environmental control system for an aeronautic vehicle
CN108688818A (zh) * 2017-04-03 2018-10-23 哈米尔顿森德斯特兰德公司 涡轮辅助式机舱空气压缩机
JP2018178999A (ja) * 2017-04-03 2018-11-15 ハミルトン・サンドストランド・コーポレイションHamilton Sundstrand Corporation タービン支援キャビン空気圧縮機
CN108688816A (zh) * 2017-04-03 2018-10-23 哈米尔顿森德斯特兰德公司 混合第三空气调节组件
CN108688816B (zh) * 2017-04-03 2023-05-23 哈米尔顿森德斯特兰德公司 混合第三空气调节组件
US10526092B2 (en) * 2017-04-03 2020-01-07 Hamilton Sundstrand Corporation Turbine-assisted cabin air compressor
EP4074601A1 (de) * 2017-04-03 2022-10-19 Hamilton Sundstrand Corporation Turbinenunterstützter kabinenluftkompressor
EP3385170A1 (de) * 2017-04-03 2018-10-10 Hamilton Sundstrand Corporation Turbinenunterstützter kabinenluftkompressor
US20180281977A1 (en) * 2017-04-03 2018-10-04 Hamilton Sundstrand Corporation Turbine-assisted cabin air compressor
US10507928B2 (en) 2017-06-16 2019-12-17 Honeywell International Inc. High efficiency electrically driven environmental control system
US20190039738A1 (en) * 2017-08-01 2019-02-07 Honeywell International Inc. Cabin outflow air energy optimized cabin pressurizing system
US11661197B2 (en) * 2017-08-01 2023-05-30 Honeywell International Inc. Cabin outflow air energy optimized cabin pressurizing system
US20210039794A1 (en) * 2017-08-01 2021-02-11 Honeywell International Inc. Cabin outflow air energy optimized cabin pressurizing system
US10843804B2 (en) * 2017-08-01 2020-11-24 Honeywell International Inc. Cabin outflow air energy optimized cabin pressurizing system
US20190185167A1 (en) * 2017-10-05 2019-06-20 Liebherr-Aerospace Toulouse Sas Autonomous aircraft cabin energy recovery module and corresponding method
US11577842B2 (en) * 2017-10-05 2023-02-14 Liebherr-Aerospace Toulouse Sas Autonomous aircraft cabin energy recovery module and corresponding method
CN109665106A (zh) * 2017-10-13 2019-04-23 哈米尔顿森德斯特兰德公司 由放出空气和机舱空气驱动的补充组件
US11396378B2 (en) * 2018-01-24 2022-07-26 Hamilton Sundstrand Corporation ECS dual entry ram inlet plenum
US10988262B2 (en) 2018-03-14 2021-04-27 Honeywell International Inc. Cabin pressure control system architecture using cabin pressure air for inlet to APU core compressor
US10738703B2 (en) * 2018-03-22 2020-08-11 Raytheon Technologies Corporation Intercooled cooling air with combined features
US20190292985A1 (en) * 2018-03-22 2019-09-26 United Technologies Corporation Intercooled cooling air with combined features
US11273917B2 (en) 2018-05-29 2022-03-15 Honeywell International Inc. Cabin discharge air management system and method for auxiliary power unit
US10954865B2 (en) 2018-06-19 2021-03-23 The Boeing Company Pressurized air systems for aircraft and related methods
US10774874B2 (en) * 2018-08-06 2020-09-15 General Electric Company Fluid bearing assembly
US20210221521A1 (en) * 2018-11-06 2021-07-22 Ihi Corporation Aircraft air conditioning device
US12097961B2 (en) * 2018-11-06 2024-09-24 Ihi Corporation Aircraft air conditioning device
US11465757B2 (en) * 2018-12-06 2022-10-11 The Boeing Company Systems and methods to produce aircraft cabin supply air
US11260979B2 (en) 2019-05-31 2022-03-01 Hamilton Sundstrand Corporation Aircraft environmental control system
US11629870B2 (en) 2020-03-17 2023-04-18 Hamilton Sundstrand Corporation ECS using cabin outflow air as an electricity source
US11702219B2 (en) 2020-10-09 2023-07-18 Airbus Defence and Space GmbH Air direction arrangement for an aircraft with integrated heat exchanger
DE102020006235A1 (de) 2020-10-09 2022-04-14 Airbus Defence and Space GmbH Luftleitanordnung für ein Luftfahrzeug mit integriertem Wärmetauscher
US11619177B2 (en) 2020-11-06 2023-04-04 Ge Aviation Systems Llc Combustion engine including turbomachine
US11486315B2 (en) 2020-11-06 2022-11-01 Ge Aviation Systems Llc Combustion engine including turbomachine
US12031488B2 (en) 2020-11-06 2024-07-09 Ge Aviation Systems Llc Combustion engine including turbomachine
EP4005925A1 (de) * 2020-11-30 2022-06-01 Hamilton Sundstrand Corporation Raumluftarchitektur mit einzelluftkreislaufmaschine und hochdruckwasserabscheider
US11674435B2 (en) 2021-06-29 2023-06-13 General Electric Company Levered counterweight feathering system
US11795964B2 (en) 2021-07-16 2023-10-24 General Electric Company Levered counterweight feathering system

Also Published As

Publication number Publication date
DE69835054T3 (de) 2011-06-09
DE69835054T2 (de) 2007-02-08
EP0888966A2 (de) 1999-01-07
EP0888966B1 (de) 2006-06-28
EP0888966B2 (de) 2011-01-19
DE69835054D1 (de) 2006-08-10
EP0888966A3 (de) 2001-01-31

Similar Documents

Publication Publication Date Title
US5967461A (en) High efficiency environmental control systems and methods
US6189324B1 (en) Environment control unit for turbine engine
US4374469A (en) Variable capacity air cycle refrigeration system
US10584635B2 (en) All CO2 aircraft
US5956960A (en) Multiple mode environmental control system for pressurized aircraft cabin
US5511374A (en) High pressure air source for aircraft and engine requirements
US6526775B1 (en) Electric air conditioning system for an aircraft
US3878692A (en) Aircraft cabin cooling method and apparatus
US6124646A (en) Aircraft air conditioning system including electric generator for providing AC power having limited frequency range
US5860283A (en) Environmental control system
US4419926A (en) ESC energy recovery system for fuel-efficient aircraft
US5056335A (en) Auxiliary refrigerated air system employing input air from turbine engine compressor after bypassing and conditioning within auxiliary system
US6796131B2 (en) Environmental control system
US5036678A (en) Auxiliary refrigerated air system employing mixture of air bled from turbine engine compressor and air recirculated within auxiliary system
US4535606A (en) High efficiency air cycle air conditioning system
EP3385169A1 (de) Dritte hybridklimaanlage
EP3103721B1 (de) Rückführungssystem für parallele ram-wärmetauscher
CN105857618B (zh) 利用并联冲压式热交换器的环境控制系统
CN102917950A (zh) 用于飞行器的使用混合操作的空气调节系统
EP1279594B1 (de) Luftkreislauf-Klimaanlage
US4840036A (en) Air cycle refrigeration system
US6101806A (en) Tri-mode combustion system
US3097508A (en) Air conditioning
EP1491443B1 (de) Klimatisierungssystem
EP3757389B1 (de) Motorkühlsysteme

Legal Events

Date Code Title Description
AS Assignment

Owner name: MCDONNELL DOUGLAS CORPORATION, MISSOURI

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FARRINGTON, FRANKLIN D.;REEL/FRAME:008671/0934

Effective date: 19970619

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12